بررسی آزمایشگاهی عملکرد فرآیند الکتروفنتون در کاهش بار آلودگی فاضلاب کاستیک‌مستعمل پالایشگاه اصفهان

نوع مقاله : مقاله پژوهشی

نویسندگان

1 گروه مهندسی شیمی، دانشکده فنی و مهندسی، دانشگاه اصفهان، اصفهان، ایران واحد آب برق بخار، پالایشگاه نفت اصفهان، اصفهان، ایران

2 گروه مهندسی شیمی، دانشکده فنی و مهندسی، دانشگاه اصفهان، ایران

3 واحد آب برق بخار، پالایشگاه نفت اصفهان، ایران

چکیده

فاضلاب کاستیک مستعمل به دلیل قلیائیت بالا، حضور ترکیبات گوگردی، بار آلودگی بالا و زیست تخریب ناپذیری از مهم‌ترین چالش‌های زیست‌محیطی پالایشگاه‌ها به‌شمار می‌رود. در همین راستا، در این پژوهش مهم‌ترین عوامل فرآیندی تأثیرگذار بر بازده فرآیند اکسیداسیون پیشرفته الکتروفنتون شامل: پی اچ (در گستره 5-2)، نسبت هیدروژن پراکسید به میزان اکسیژن‌خواهی شیمیایی (75/0-2/0= H2O2/COD)، دما (C° 60-20)، زمان واکنش (min 135-45) و دانسیته جریان (mA/cm2 20-5)، به‌صورت هم‌زمان در کاهش بار آلودگی کاستیک مستعمل پالایشگاه نفت اصفهان به کمک طراحی آزمایش‌ها با روش سطح پاسخ (RSM) مورد بررسی قرار گرفت. نتایج تجربی نشان داد عوامل H2O2/COD، دما، پی اچ، دانسیته جریان و زمان واکنش به‌ترتیب بیشترین اثر را بر بازدهی واکنش داشتند. زمان‌ماند min 60، pH برابر 5/4، نسبت H2O2/COD برابر 6/0، دانسیته جریان mA/cm2 15 و دمای C° 60 به‌عنوان شرایط بهینه فرآیندی ارزیابی شد که بازدهی نهایی 96% را برای فرآیند الکتروفنتون برحسب شاخص COD در پی داشت. همچنین داده‌های تجربی نشان داد که با تغییر COD اولیه فاضلاب در محدوده (mg/L 60000 -12500) در شرایط بهینه، بازدهی کاهش بار آلودگی کاستیک مستعمل در گستره 94% تا 97% برحسب شاخص COD قرار داشت.
 

کلیدواژه‌ها


عنوان مقاله [English]

Treatment of Isfahan Refinery Spent Caustic by Electro-Fenton Process

نویسندگان [English]

  • kourosh Nasr Esfahany 1
  • Mehrdad Farhadian 2
  • Ali Reza Solaimany Nazar 2
  • Ghasem Ghafari 3
1 hemical Engineering Department, Faculty of Engineering, University of Isfahan, Iran/Environmental Research Institute, University of Isfahan, Iran
2 hemical Engineering Department, Faculty of Engineering, University of Isfahan, Iran
3 Isfahan Oil Refining Company, Isfahan, Iran
چکیده [English]

Spent caustic wastewater is one of the most important environmental challenges due to high alkalinity, the presence of sulfur compounds and non-biodegradable pollutants. Therefore, in this research, the effective parameters of Electro-Fenton process including pH range (2-5), H2O2/COD (0.2- 0.745), temperature (20-60 °C), reaction time (45- 135 min) and current density (5-20 mA/cm2) have been investigated on the COD removal efficiency by adopting response surface methodology (RSM). The results indicated that H2O2/COD, temperature, pH, current density and reaction time have the most effect on the pollutants removal, respectively. The optimum conditions have been found at pH =4.8, current density =14.8 mA/cm2, temperature =57 °C, reaction time =63 minutes and H2O2/COD =0.63 with 96% COD removal efficiency. According to the results, by changing of initial COD within 12,500 to 60,000 mg/L range at the optimum conditions, the pollutant removal efficiency has been increased from 94% to 97%.
 

کلیدواژه‌ها [English]

  • Spent Caustic
  • Electro-Fenton
  • AOP
  • Wastewater Treatment
  • Environment
[1]. Madsen E. L., “Environmental microbiology: from genomes to biogeochemistry,” Cornell University: Wiley-Blackwell, 2008.##
[2]. Alnaizy R., “Economic analysis for wet oxidation processes for the treatment of mixed refinery spent caustic,” Environmental Progress, Vol. 27, pp. 295–351, 2008.##
[3]. Sawyer C. N., McCarty P. L., and Parkin G. F., “Chemistry for environmental engineering and science,” 5th ed., New York: McGraw-Hill, 2003.##
[4]. Veerabhadraiah G., Mallika N., and Jindal S., “Spent caustic management: Remediation review proper disposal of spent caustic requires full understanding of waste components,” Hydrocarbon Processing, Vol. 90, No. 11, pp. 41-46, 2011.##
[5]. Ben Hariz I., Halleb A., Adhoum N., and Monser L., “Treatment of petroleum refinery sulfidic spent caustic wastes by electrocoagulation,” Separation and Purification Technology, Vol. 107, pp. 150-157, 2013.##
[6]. Ellis E. C., “Wet air oxidation of refinery spent caustic,” Environmental Progress, Vol. 17, 1998.##
[7]. Samadiafshar A., “Study on basic methods of spent caustic treatment,” The First International Conference Oil, Gas, Petrochemical and Power Plant, University of Tehran, Tehran, 2012.##
[8]. Schoonen M. A. A. and Barnes H. L., “An approximation of the second dissociation constant for H2S, Geochimica et Cosmochimica Acta, Vol. 52, No. 3, pp. 649-654, 1988.##
[9]. de Graaff M., Bijmans M. F. M., Abbas B., Euverink G. J. W., Muyzer G., and Janssen A. J. H., “Biological treatment of refinery spent caustics under halo-alkaline conditions,” Bioresource Technology, Vol. 102, No. 15, pp. 7257-7264, 2011.##
[10]. Kumfer B., Felch C., and Maugans C., “Wet air oxidation treatment of spent caustic in petroleum refineries,” National Petroleum Refiner’s Association Conference, Phoenix. ,pp. 21-23, 2010.##
[11]. Keramati N., Moheb A., and Ehsani M.R., “Application of ED and EDI processes in NaOH recovery from Merox spent caustic waste,” International Conference on Advances in Wastewater Treatment and Reuse, University of Tehran, Tehran, 2009.##
[12]. رضایی ح.، صمدبین ا.، غلامی ن.، فرخانی د.، و بزمی م.، "بررسی اثر افزایش حلال و دمولسیفایر در گوگردزدایی از کاستیک واحدهای مرکاپتانزدایی،" مجله پژوهش نفت، دوره 25، شماره 83 ، صفحات 24-32، 1394.##
[13]. Arena F., Di Chio R., Gumina B., Spadaro L., and Trunfio G., “Recent advances on wet air oxidation catalysts for treatment of industrial wastewaters,” Inorganica Chimica Acta, Vol. 431, pp. 101-109, 2015.##
[14]. Gameel A., Malash G., Mubarak A. A., and Hussein M., “Treatment of spent caustic from ethylene plant using electro-Fenton technique,” American Journal of Environmental Engineering and Science, Vol. 2, No. 4, pp. 37-46, 2015.##
[15]. Cheng M., Zeng G., Huang D., Lai C., Xu P., Zhang C., and Liu Y., “Hydroxyl radicals based advanced oxidation processes (AOPs) for remediation of soils contaminated with organic compounds: A review,” Chemical Engineering Journal, Vol. 284, pp. 582-598, 2016.##
[16]. Rodriguez N., Hansen H. K., Nunez P., and Guzman J., “Spent caustic oxidation using electro-generated Fenton›s reagent in a batch reactor,” Journal of Environmental Science and Health - Part A Toxic/Hazardous Substances and Environmental Engineering, Vol. 43, No. 8, pp. 952-960, 2008.##
[17]. Virkutyte J., Jegatheesan V., “Electro-Fenton, hydrogenotrophic and Fe2+ ions mediated TOC and nitrate removal from aquaculture system: different experimental strategies,” Bioresour Technology, Vol. 100, No. 7, pp. 2189-2197, 2009.##
[18]. Babuponnusami A. and Muthukumar K., “Advanced oxidation of phenol: A comparison between Fenton, electro-Fenton, sono-electro-Fenton and photo-electro-Fenton processes,” Chemical Engineering Journal, Vol. 18, pp. 1-9, 2012.##
[19]. Nuñez P., Hansen H. K., Rodriguez N., Guzman J., and Gutierrez C., “Electrochemical generation of Fentonꞌs reagent to treat spent caustic wastewater,” Separation Science and Technology, Vol. 44, No. 10, pp. 2223-2233, 2009.##
[20]. Sheu S. and Weng H. S., “Treatment of olefin plant spent caustic by combination of neutralization and Fenton reaction,” Water Research, Vol. 35, pp. 2017–2021, 2001.##
[21]. Oh S. Y. and Shin D. S., “Degradation of spent caustic by Fenton and persulfate oxidation with zero-valent iron,” Journal of Chemical Technology & Biotechnology, Vol. 88, No.1, pp. 145-152, 2013.##
[22]. Hawari A., Ramadan H., Abu-Reesh I., and Ouederni M., “A comparative study of the treatment of ethylene plant spent caustic by neutralization and classical and advanced oxidation,” Journal of Environmental Management, Vol. 151, pp. 105-12, 2015.##
[23]. Babuponnusami A. and Muthukumar K., “Degradation of Phenol in aqueous solution by Fenton, sono-Fenton and sono-photo-Fenton methods,” Clean  Soil, Air, Water, Vol. 39, No. 2, pp. 142-147, 2011.##
[24]. Özcan A., Şahin Y., Koparal A. S. and Oturan M. A., “A comparative study on the efficiency of electro-Fenton process in the removal of propham from water,” Applied Catalysis B: Environmental, Vol. 89, No. 3-4, pp. 620-626, 2009.##
[25]. Martínez-Huitle C. A. and Brillas E., “Decontamination of wastewaters containing synthetic organic dyes by electrochemical methods: A general review,” Applied Catalysis B: Environmental, Vol. 87, No. 3-4, pp. 105-145, 2009.##
[26]. Garcia-Segura S., El-Ghenymy A., Centellas F., Rodríguez R. M., Arias C., Garrido J. A., Cabot P. L., and Brillas E., “Comparative degradation of the diazo dye Direct Yellow 4 by electro-Fenton, photoelectro-Fenton and photo-assisted electro-Fenton,” Journal of Electroanalytical Chemistry, Vol. 681, pp. 36-43, 2012.##
[27]. Martinez S. S. and Uribe E. V., “Enhanced sonochemical degradation of azure B dye by the electroFenton process,” Ultrason Sonochem, Vol. 19, No. 1, pp. 174-8, 2012.##
[28]. Tony M.A., Purcell P.J., and Zhao Y., “Oil refinery wastewater treatment using physicochemical, Fenton and Photo-Fenton oxidation processes,” Journal of Environmental Science and Health-Part A Toxic/Hazardous Substances and Environmental Engineering, Vol. 47, No. 3, pp. 435-40, 2012.##
[29]. Pozza A., Ferrantelli P., Merli C., and Petrucci E., “Oxidation efficiency in the electro-Fenton process,” Journal of Applied Electrochemistry, Vol. 35, No. 4, pp. 391-398, 2005.##